Daily Chemicals: Ancient Times - Chemicals from Stamps (Nine)

Figure (1) Traditional wool-stained stamps issued by Transkay.
(2) Leather processing stamps issued by Niger.
(3) The paint box of the Qing Dynasty
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commonly used in chinese life in ancient times, such as pigments, dyes, paints, cosmetics, fragrances, leather, etc. , they are closely related to chemical development.
ancients began to use paint from an early stage, when the name "big paint", divided into raw paint and refined paint two kinds. Raw paint is a milky, viscous liquid that flows out of the ligament layer of a cut-out lacquer tree, and is the secretion of the metabolism of the lacquer tree. Raw paint is heated at low temperature, removing moisture to become refined paint, also known as cooked paint. Painted wood, dry on a layer of solid, bright film, not only to protect the material, but also bright and beautiful, with heat, acid, alkali-resistant function. China from the Neolithic era has known the performance of lacquer and used in the making of equipment, after the business week until the Ming and Qing, China's lacquer process continued to develop, reached a very high level.
the War Of War, the production scale of lacquer has been very large, is an important economic source of the country, and set up a special management. Lacquer production process is complex, labor-consuming, a wide variety, not only used to decorate furniture, utensils, stationery and art, but also used in musical instruments, funeral utensils, weapons and so on. China's lacquer and lacquer technology has been transmitted to foreign countries very early, many countries around the Han and Tang Dynasty have mastered the paint technology, and produce their own characteristics of lacquer. Chinese lacquer was also passed on to Europe by Persians and Arabs, and was very popular.
china had set up a special department in charge of dyeing during the Zhou Dynasty. After Qin and Han Dynasty, the production and application of plant dyes also grew with the enrichment and development of herbology in practice exploration. By the Time of the Ming and Qing, the number of plants used in dyeing had expanded to dozens of species.
in traditional vegetable dyes, red dyes are mainly red flowers, grass, sumu and so on. Semen is a weak alkaline substance, soluble in alkaline solution, in neutral or weak acidic solution will produce bright red precipitation, so it is the main plant dye of ancient red dye. Purple dye is purple grass, is a perennian herb, its roots contain acetyl purple grass ning, in the wood ash, alum and other dyes can be used to turn the fiber into fuchsia. Black dyes are mainly double, chestnut shell, lotus shell, fruit, etc. , are containing more tanned substances, they are combined with green, and then oxidized by air, that is, black.
commonly used cosmetics in ancient China are mainly powder, Dai, fat and other categories. Powder is mainly used to modify the skin, especially the face. The powders commonly used by the ancients were rice flour and lead powder. Lead powder, or alkaline lead carbonate, can not only be used as a white pigment, but also used in the surface. Lead powder has been used in modern times, and later because of the discovery of lead powder in the face due to oxidation and some harm to the skin, began to use with caution. Dai is a black mineral used to draw eyebrows. Dai has black, but also other colors, such as Hudders, Green, Qing Dai and so on. Grease is an oily material, used to moisturize hair, "Zimin to the art" of yan (sic) fat system has been recorded in detail.
the first detergent people used to do laundry was grass ash. The main chemical components of grass ash are potassium carbonate and sodium carbonate, and people know later that natural sodium carbonate can be used as a detergent until after gold and yuan. Because grass and ash can be sourced locally and from a wide range of sources, they also take longer to follow. Soap because it contains saponin, its aqueous solution is a strong emulsifying agent, has the function of descaling, many places in China use this to wash.
leather processing is also the earliest human chemical principles to create the art. In primitive societies, stone tools were used to peel off animal skins and sew them into clothing or utensils. The wet skin after just peeling is soft, but after drying out, it becomes very stiff, difficult to sew and process, and wears armor on the body, which is very uncomfortable.
later, people gradually groped out the use of wild animal bone marrow, oil and other smeared on the surface of raw skin, and then through the sun's rays and palms, so that the skin of the beast soft and not easy to decay. This method is actually the oil is oxidized by the air to produce aldehyde, as a tanner processing leather. At that time, there was also a method of smoking processing raw skin, this smoked tanning method is also due to aldehyde in the smoke. There are also raw skins soaked in the juice of bark or branches, in fact, the use of certain plants containing tannins as a tanning agent. Later, people are more likely to soak in lime water raw skin hair, and then use mannitro or alum, salt and yogurt to tan.
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